JP2002235625A - Electric fuel pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric fuel pump reducing the load of a battery of reducing the consumed current and eliminate the lowering of a discharge quantity by preventing vaporization of the fuel by Joule heat in a rotor winding in a system using the electric fuel pump. SOLUTION: A pressure regulator 30 regulating the pressure of fuel discharged from a fuel outlet 23 is disposed in a pump casing assembly body 1. When the fuel pressure discharged from the discharge port 9 reaches a prescribed pressure or more, the fuel is returned to the adjacency to an inlet 8 so as to reduce the load torque applied to the rotor 16 of a motor 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel pump housed in a fuel tank in a vehicular internal combustion engine and for pumping fuel in the fuel tank to an engine of the internal combustion engine. Things.

[0002]

2. Description of the Related Art FIG. 7 is a longitudinal sectional view showing a conventional electric fuel pump disclosed, for example, in Japanese Patent Publication No. 7-3239, FIG. 8 is a sectional view taken along line CC of FIG. 7, and FIG. FIG. 4 is a characteristic curve diagram showing the performance of a fuel pump.

In the drawing, reference numeral 1 denotes an assembly of a pump casing. The pump casing assembly 1 is composed of a pump casing body 2 and a cover 3, and a disk-shaped outer casing is provided inside the pump casing assembly 1. An impeller 4 which is a rotating body having a blade portion 5 is housed along a peripheral edge portion, and an arc-shaped band-shaped pump flow path 7 is provided along the blade portion 5 of the impeller 4 over the pump casing body 2 and the cover 3. In the cover 3 at both ends of the pump flow path 7, suction ports 8 are opened downward from one surface of the impeller 4 in FIG. 7, and the discharge ports 9 are formed in the pump casing body 2.
Open upward from the other surface of the impeller 4.

The center shaft 6 of the rotor 16 of the electric motor 15 is inserted into the center of the impeller 4. The rotor 16 includes a bearing 17 having the center shaft 6 disposed on the pump casing body 2 and the bracket 24, respectively. It is supported by bearings 18 and is rotatable. Reference numeral 19 denotes an end cover made of, for example, a thermoplastic resin molded product. The pump casing assembly 1 and the end cover 19 are connected to a cylindrical yoke 20 of the electric motor 15.
The permanent magnet 25 is annularly disposed on the inner periphery of the yoke 20, and the rotor 16 is housed inside the permanent magnet 25.

A fuel chamber 21 for storing fuel discharged from the discharge port 9 is provided between the pump casing assembly 1 and the end cover 19, and is provided on an end face of the fuel chamber 21 and the end cover 19. The fuel outlet 23 is in communication, and a check valve 22 for regulating the direction in which fuel flows is provided in the middle of the passage. Reference numeral 27 denotes a power supply brush for supplying a current to a winding (not shown) of the rotor 16 via the commutator 26.

Next, the operation of the conventional electric fuel pump formed as described above will be described. In the electric fuel pump configured as described above, when current is supplied to the winding (not shown) of the rotor 16 of the electric motor 15 via the power supply brush 27 and the commutator 26, the impeller 4 rotates The fuel is drawn into one end of the pump flow path 7 from the suction port 8 by being rotationally driven (indicated by an arrow in FIG. 8) in the circumferential direction, and this fuel flows through the pump flow path 7 in the clockwise direction. The pressure is increased and the fuel chamber 21 is discharged from the discharge port 9 at the other end.
And is discharged from the fuel discharge port 23 through the check valve 22.

The performance of the electric fuel pump (shown in FIG. 9)
The horizontal axis represents the fuel pressure (P) of the fuel discharged from the electric fuel pump, and the vertical axis represents the discharge amount (Q) of the fuel discharged from the electric fuel pump and the current consumption (I) of the electric fuel pump. The fuel discharged from the fuel outlet 23 of the electric fuel pump is adjusted to a predetermined pressure (P1) by a pressure regulator (not shown) and then supplied to an engine (not shown) of the vehicle internal combustion engine. Is done.

The pressure regulator is disclosed in, for example, Japanese Patent Application Laid-Open No. 8-1.
As shown in JP 77681, it is provided separately from the electric fuel pump. In this case, when the fuel pressure discharged from the fuel outlet 23 of the electric fuel pump is adjusted to P1 (shown in FIG. 9) by a pressure regulator (also referred to as a fuel pressure regulator), the electric fuel pump discharges. Q1,
It is formed so as to operate continuously with the consumption current I1, and assuming that the fuel consumption amount consumed by the engine is q (not shown), the discharge amount Q discharged from the electric fuel pump is
Q1-q obtained by subtracting q of the fuel consumption from 1 is surplus fuel, and is fed back from the pressure regulator into the fuel tank without being supplied to the engine.

[0009]

As described above, the conventional electric fuel pump continuously discharges the discharge amount (Q1) including the excess fuel larger than the fuel consumption amount (q) required by the engine. Current consumption (I
1) is large and not only burdens a battery (not shown) mounted on the vehicle internal combustion engine, but also causes fuel flowing through the electric fuel pump to vaporize due to Joule heat in the winding of the rotor 16 due to current consumption. As a result, there is a problem that the discharge amount discharged from the fuel outlet 23 decreases.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and the electric fuel pump is operated without waste according to the fuel consumption of the engine to reduce the current consumption and reduce the load on the battery. It is an object of the present invention to provide an electric fuel pump that reduces the amount of fuel discharged from a fuel outlet by preventing fuel from being vaporized due to Joule heat in a rotor winding.

[0011]

An electric fuel pump according to the present invention is provided with a pump casing assembly for sucking fuel from a suction port and discharging from a discharge port by rotation of a rotating body housed therein, and engaging with the rotating body. An electric motor for rotating the rotating body, a fuel outlet for discharging fuel discharged from the discharge port to the engine of the internal combustion engine, and a pressure regulator for adjusting a fuel pressure discharged from the fuel discharge port. In the electric fuel pump, the pressure regulator adjusts the fuel pressure discharged from the fuel discharge port by returning fuel to the vicinity of the suction port when the fuel pressure discharged from the discharge port is equal to or higher than a predetermined pressure. Is what you do.

Further, the pressure regulator is provided in a regulator accommodation hole of the pump casing assembly.

The pressure regulator includes a valve for controlling a flow rate of fuel returned to the vicinity of the suction port based on a fuel pressure discharged from the discharge port, a spring for determining a pressure at which the valve opens and closes, and a spring for holding the spring. Formed by a spring holder.

Further, an elastic body is provided on the surface of the valve which comes into contact with the pump casing body.

Further, the valve is formed by an elastic body having a fitting convex portion and a spring receiver having a fitting concave portion, and the fitting convex portion is fitted into the fitting concave portion to form the elastic body and the spring. It is the one that united.

Further, the spring is formed by a coil spring, and one end of the spring is fitted to the valve and the other end is fitted to the spring holder, so that the valve and the spring holder are integrally held.

Further, the spring holder is fixed at a predetermined position on the inner peripheral surface of the adjuster housing hole.

Further, a notch is provided in a peripheral portion of the spring holder.

Further, the rotating body is an impeller having a blade portion on an outer peripheral portion.

Further, the electric motor has a rotor in which a central shaft engaged with the rotating body is inserted, a bearing for supporting the central shaft and enabling the rotor to rotate, and concentric with the outer periphery of the rotor. It is formed by a pair of permanent magnets, a commutator for supplying a current to the windings of the rotor, and a power supply brush.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 1 is a longitudinal sectional view showing an electric fuel pump according to Embodiment 1 of the present invention, FIG. 2 is a sectional view taken along line AA of FIG. 1, FIG. 3 is a partially enlarged sectional view of a pressure regulator, and FIG. FIG. 5 is a characteristic curve diagram showing the performance of the electric fuel pump according to the first embodiment of the present invention.

1 to 4, reference numeral 1 denotes an assembly of a pump casing. This pump casing assembly 1 is composed of a pump casing body 2 and a cover 3, and a circle is formed inside the pump casing assembly 1. An impeller 4 which is a plate-shaped rotating body having blades 5 along the outer peripheral edge is housed, and the arc-shaped pump extends across the pump casing body 2 and the cover 3 along the blades 5 of the impeller 4. A flow path 7 is formed, and a suction port 8 is opened downward from FIG. 1 from one surface of the impeller 4 in the cover 3 at both ends of the pump flow path 7, and a discharge port is formed in the pump casing body 2. 9 opens upward from the other surface of the impeller 4.

The center shaft 6 of the rotor 16 of the electric motor 15 is inserted into the center of the impeller 4. The rotor 16 includes a bearing 17 having the center shaft 6 disposed on each of the pump casing body 2 and the bracket 24. It is supported by bearings 18 and is rotatable. Reference numeral 19 denotes an end cover made of, for example, a thermoplastic resin molded product. The pump casing assembly 1 and the end cover 19 are connected to a cylindrical yoke 20 of the electric motor 15.
The permanent magnet 25 is annularly disposed on the inner periphery of the yoke 20, and the rotor 16 is housed inside the permanent magnet 25.

A fuel chamber 21 for storing fuel discharged from the discharge port 9 is provided between the pump casing assembly 1 and the end cover 19, and is provided on an end face of the fuel chamber 21 and the end cover 19. The fuel outlet 23 is in communication, and a check valve 22 for regulating the direction in which fuel flows is provided in the middle of the passage. Reference numeral 27 denotes a power supply brush for supplying a current to a winding (not shown) of the rotor 16 via the commutator 26.

Reference numeral 2a denotes a fuel return hole provided in the pump casing body 2 of the pump casing assembly 1, one end of which is open to the fuel chamber 21. Reference numeral 2b denotes a regulator housing hole disposed in the pump casing main body 2 and communicating with the other end opening of the fuel return hole 2a. The diameter of the storage hole is larger than the diameter of the fuel return hole 2a. Reference numeral 2c denotes an inner peripheral surface of the adjuster housing hole 2b. The fuel chamber 21 and the pump flow path 7 near the suction port 8 communicate with each other through a fuel return hole 2a and a regulator housing hole 2b.

Reference numeral 30 denotes a pressure regulator housed in the regulator housing hole 2b. The pressure regulator 30 normally closes the fuel return hole 2a and opens and sucks when the pressure of the fuel discharged from the discharge port 9 into the fuel chamber 21 is higher than a predetermined pressure, for example, P1 (shown in FIG. 5). A valve 31 for returning fuel to the vicinity of the port 8,
The spring 3 that determines the pressure at which the valve 31 opens and closes
2 and an annular spring holder 33 that is fitted into the inner peripheral surface 2c of the adjuster housing hole 2b and holds the spring 32.

The valve 31 is formed by combining an elastic body 31a and a spring receiver 31b. The elastic body 31a provided on the surface of the pump casing body 2 which is in contact with the peripheral edge of the other end opening of the fuel return hole 2a is To ensure airtightness, for example, a rubber molded product is used, and a spring 32 is used.
For the spring receiver 31b that comes into contact with, for example, a metal plate such as a stainless steel plate or a resin plate made of a phenol resin material, which is a high-rigidity material that is not deformed by the load of the spring 32 when the spring 32 comes into contact, is used.

The elastic body 31a has an anchor-shaped fitting projection 31a1.
And the fitting projection 31a1 is
Fitting recess 31b formed by burring or the like
The elastic body 31a and the spring receiver 31b are integrated with each other by being fitted into the inner peripheral portion of the first elastic member 31. The elastic body 3
1a may be made of a film and the spring receiver 31b may be covered.

The function of the valve 31 is that the valve 31 is pressed against the pump casing body 2 (the fuel chamber 21).
When the internal pressure is equal to or lower than a predetermined pressure).
This is to prevent the fuel in 1 from leaking to the vicinity of the suction port 8. Instead of the above-described two-part structure (elastic body 31a and spring receiver 31b), it is made into one part and has good flatness, for example, metal. A plate, a resin plate, or the like may be used. As the spring 32, a coil spring formed of a stainless steel wire is used. For example, any spring that biases the valve 31 and the spring holder 33 in opposite directions may be used.
A leaf spring or the like may be used.

The spring holder 33 is provided with, for example, four notches 33a at equal intervals on the outer peripheral edge and a burring portion 33b at the center. This notch 3
3a forms a passage through which fuel returned to the suction port 8 flows, and reduces the rigidity of the spring holder 33 to facilitate the insertion of the spring holder 33 into the inner peripheral surface 2c of the adjuster housing hole 2b. And the burring portion 33b holds the spring 32.

Next, the valve 3 forming the pressure regulator 30
1. A method of incorporating the spring 32 and the spring holder 33 into the adjuster housing hole 2b will be described. (1) The inner peripheral surface at one end of the spring 32 is inserted into the outer peripheral surface of the fitting concave portion 31b1 of the spring receiver 31b. At this time, since the inner peripheral surface dimension of the spring 32 is set smaller than the outer peripheral surface dimension of the fitting recess 31b1, the spring 32 is held while being pressed into the spring receiver 31b.

(2) Next, the other end of the spring 32 is fitted into the outer peripheral surface of the burring portion 33b of the spring holder 33. At this time, since the inner peripheral surface dimension of the spring 32 is set smaller than the outer peripheral surface dimension of the burring portion 33b, the spring holder 33 is held while being pressed into the spring 32, and the valve 31 and the spring holder 3
3 are integrally connected via a spring 32.

(3) Next, the integrally connected valve 3
1. Insert the spring 32 and the spring holder 33 (pressure regulator 30) into the regulator accommodation hole 2b, and push the outer peripheral surface of the spring holder 33 along the inner peripheral surface 2c to a predetermined position in the upward direction in FIG.

Next, the operation of the electric fuel pump configured as described above will be described with reference to FIGS. First, a case where the engine of the vehicle internal combustion engine equipped with the electric fuel pump is not consuming fuel, for example, in a stopped state, will be described. (1) Winding of rotor 16 of motor 15 (not shown)
Then, when a current is supplied through the power supply brush 27 and the commutator 26, the rotor 16 rotates, and the impeller 4 is driven to rotate clockwise through the center shaft 6 (FIG. 2).

(2) When the blade 5 on the outer periphery of the impeller 4 rotates along the arc-shaped pump flow path 7, a swirling flow is generated in the blade 5, and the kinetic energy increases with the rotational movement. (Preferably a negative pressure near the suction port 8 and a positive pressure near the discharge port 9), the fuel is sucked from the suction port 8 into one end of the pump flow path 7, and the fuel flows into the pump flow path 7. The pressure is increased while flowing clockwise through 7,
The fuel chamber 21 through the discharge port 9 from the other end of the pump flow path 7
Is discharged to

(3) The fuel that has flowed into the fuel chamber 21 attempts to be discharged from the fuel outlet 23 through the check valve 22 to the engine of the internal combustion engine (not shown). Since the state is the same as the state where the outlet 23 is closed, the fuel pressure in the fuel chamber 21 sharply increases.

(4) When the fuel pressure in the fuel chamber 21 reaches P1 (FIG. 5), the valve 31 is opened, and the fuel in the fuel chamber 21 is supplied from the fuel return hole 2a through the opening / closing portion of the valve 31, the regulator storage hole. 2b, notch 3 provided in spring holder 33
The fuel pressure in the fuel chamber 21 is raised to P1 without returning to the vicinity of the suction port 8 through the portion 3a, thereby increasing the fuel pressure.
Is held. The discharge amount at this time is Q0.

The fuel pressure in the fuel chamber 21 can be changed by setting the position where the spring holder 33 is inserted into the inner peripheral surface 2c of the adjuster housing hole 2b. For example, the spring holder 33 is pushed in. (Upward direction in Fig. 3)
Thus, the fuel pressure can be set high.
(P2 in FIG. 5)

Next, the operation of the electric fuel pump when the fuel consumption changes while the engine of the vehicle internal combustion engine is operating and the electric fuel pump is discharging fuel will be described. (1) The fuel pressure P1, the discharge amount Q1 discharged from the fuel discharge port 23 to the engine by the electric fuel pump, and the consumption current I1
(Q1 and I1 in FIG. 5). At this time, in this description, it is assumed that the valve 31 is closed and all the fuel discharged from the discharge port 9 is discharged from the fuel chamber 21 through the check valve 22 to the engine through the fuel discharge port 23. However, it may be set so that a small amount is returned from the fuel return hole 2a to the vicinity of the suction port 8 through the opening / closing portion of the valve 31, the adjuster housing hole 2b, and the notch 33a provided in the spring holder 33. .

(2) When the fuel consumption of the engine (= discharge amount discharged from the fuel discharge port 23) decreases from Q1 to Q2, the fuel pressure in the fuel chamber 21 increases, but the valve 31 opens and the fuel The fuel in the chamber 21 is returned from the fuel return hole 2a to the vicinity of the suction port 8 through the opening / closing portion of the valve 31, the regulator accommodating hole 2b, and the notch 33a provided in the spring holder 33. Is maintained at P1.

(3) When the pressurized fuel from the fuel chamber 21 is returned to the suction port 8, the negative pressure generated in the vicinity of the suction port 8 is relieved and applied to the rotor 16 via the central shaft 6. Since the applied load torque decreases, the current consumption of the electric motor 15 (electric fuel pump) decreases from I1 to I2.

(4) The fuel consumption of the engine (= discharge amount discharged from the fuel discharge port 23) further decreases, and when it reaches Q3, the opening / closing portion of the valve 31 through the fuel return hole 2a, the regulator housing hole 2b, The amount of fuel returned to the vicinity of the suction port 8 through the notch 33a provided in the spring holder 33 increases, the negative pressure generated near the suction port 8 is further reduced, and the rotor 16 Since the load torque applied to the motor 15 further decreases, the current consumption of the electric motor 15 (electric fuel pump) decreases to I3.

(5) When the fuel consumption of the engine (= discharge amount discharged from the fuel discharge port 23) increases to Q2,
When the fuel pressure in the fuel chamber 21 decreases, the fuel return hole 2a, the opening / closing portion of the valve 31, and the regulator housing hole 2
b, the amount of fuel returned to the vicinity of the suction port 8 via the notch 33a provided in the spring holder 33 decreases, the negative pressure generated near the suction port 8 increases, and the fuel chamber The fuel discharged to the fuel chamber 21 is increased,
P1 is maintained by increasing the fuel pressure in the inside. At this time, the load torque of the rotor 16 increases via the center shaft 6 with an increase in the negative pressure, so that the current consumption of the electric motor 15 (electric fuel pump) increases to I2.

(6) Thereafter, similarly, when the fuel consumption of the engine increases or decreases, the fuel is returned from the fuel chamber 21 to the fuel return hole 2a, the opening / closing portion of the valve 31, the regulator housing hole 2b, and the spring holder 33. The amount of fuel returned to the vicinity of the suction port 8 via the notch 33a increases or decreases.
, The current consumption of the electric motor 15 increases and decreases, and the fuel pressure is maintained at P1.

As described above, according to the electric fuel pump of the present invention, the electric fuel pump is operated in accordance with the fuel consumption of the engine to reduce the current consumption, reduce the load on the battery, and reduce the load on the rotor. Since fuel vaporization due to Joule heat in the windings can be prevented, it is possible to obtain an electric fuel pump in which the discharge amount discharged from the fuel discharge port does not decrease.

The above-described embodiment is a non-volume type using a disk-shaped impeller having a disk-shaped outer peripheral portion as a rotating body for generating fuel pressure.
Although the present invention may be applied to a positive displacement type using a trochoid gear disclosed in Japanese Patent Application Laid-Open No. 000-265972, the current consumption of the motor is larger in the case of the non-positive displacement type than in the case of the positive displacement type. Is effective in reducing the current consumption.

In the above-described embodiment, a DC motor formed of a commutator 26 and a power supply brush 27 that is in sliding contact with the commutator 26 is used as the electric motor 15, for example, Japanese Patent Application Laid-Open No. 2000-228890. May be used, but when the present invention is applied to a motor using a DC motor, the current consumption is reduced to reduce the current consumption.
There is an effect that wear when the brush 6 and the power supply brush 27 slide is suppressed.

Further, in the above embodiment, the pressure regulator 3
0 was stored in the regulator storage hole 2b of the pump casing assembly 1, but the fuel discharged from the discharge port 9 was
As long as it can be returned to the vicinity, it may be arranged in the electric fuel pump or on the outer peripheral surface of the yoke 20 of the electric fuel pump.

Further, as shown in FIG. 6, a pressure regulator 30 may be connected to the fuel discharge port 23 to return the fuel to the suction port 8, but the pressure regulator 30 may be provided inside the electric fuel pump. The stored one has the effect that a fuel pump system in which the mounting space for the pressure regulator 30 is reduced can be formed.

[0050]

As described above, according to the first aspect of the present invention,
A pump casing assembly that rotates a rotating body housed inside to draw fuel from an intake port and discharge it from a discharge port;
An electric motor that engages with the rotating body and rotates the rotating body;
In an electric fuel pump including a fuel outlet for discharging fuel discharged from the discharge port to an engine of an internal combustion engine, and a pressure regulator for adjusting a fuel pressure discharged from the fuel outlet, the pressure regulator is When the fuel pressure discharged from the discharge port is equal to or higher than a predetermined pressure, the fuel is returned to the vicinity of the suction port to adjust the fuel pressure discharged from the fuel discharge port. When the fuel pressure drops, the fuel discharged from the discharge port is returned to the vicinity of the suction port, reducing the load torque of the rotor and reducing the current consumption of the electric motor (electric fuel pump), thereby reducing the load on the battery. Thus, fuel vaporization due to Joule heat in the rotor windings can be prevented.

According to the second aspect of the present invention, since the pressure regulator is disposed in the regulator accommodating hole of the pump casing assembly in the electric fuel pump, the fuel pump system has a reduced space for mounting the pressure regulator. Can be formed.

According to the third aspect of the present invention, the pressure regulator includes a valve for controlling a flow rate of the fuel returned to the vicinity of the suction port based on the fuel pressure discharged from the outlet, and a pressure for opening and closing the valve. Since the spring is determined by the spring to be determined and the spring holder that holds the spring, the fuel pressure can be adjusted accurately with a simple configuration.

According to the fourth aspect of the present invention, since the elastic body is disposed on the surface of the valve that comes into contact with the pump casing main body, the valve is pressed against the pump casing main body (when the pressure in the fuel chamber becomes a predetermined value). Below pressure)
Since the airtightness between the pump casing body and the elastic body is good and the fuel in the fuel chamber does not leak near the suction port,
Good adjustment performance as a pressure regulator.

According to the invention of claim 5 or claim 6, the valve is formed by an elastic body having a fitting projection and a spring receiver having a fitting recess, and the fitting projection is fitted to the fitting projection. The elastic body and the spring receiver are integrated with each other by being inserted into a concave portion, and a spring is formed by a coil spring. One end of the spring is fitted to a valve, and the other end is fitted to a spring holder. Since the spring holder is integrally held, the valve, the spring and the spring holder are integrated, so that the incorporation into the adjuster housing hole is good.

According to the seventh aspect of the present invention, since the spring holder is fixed at a predetermined position on the inner peripheral surface of the adjuster housing hole, the spring for determining the opening / closing pressure of the valve is reliably set. The fuel pressure can be accurately set.

According to the eighth aspect of the present invention, the notch is provided in the peripheral portion of the spring holder, so that the fuel flows smoothly from the fuel chamber toward the vicinity of the suction port, and the inner circumference of the adjuster housing hole. The spring holder can be easily inserted into the surface.

According to the ninth aspect of the present invention, since the rotating body is an impeller having a blade portion on the outer peripheral portion and is applied to a non-volume type in which the electric current consumption of the motor is large, the current consumption is reduced. The effect is great and has a great effect on preventing fuel vaporization due to Joule heat in the winding of the rotor.

According to the tenth aspect of the present invention, there is provided a rotor in which a central shaft for engaging an electric motor with a rotating body is inserted, and a bearing for supporting the central shaft and enabling the rotor to rotate. ,
Since a pair of permanent magnets arranged concentrically on the outer periphery of the rotor, and a commutator and a power supply brush for supplying current to the windings of the rotor are formed, current consumption of the motor is reduced. Thus, it is possible to suppress abrasion of the commutator and the power supply brush forming the electric motor during sliding.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing Embodiment 1 of an electric fuel pump according to the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is an enlarged sectional view of a pressure regulator.

FIG. 4 is a partially enlarged cross-sectional view as viewed from B in FIG. 3;

FIG. 5 is a characteristic curve showing the performance of the electric fuel pump according to the first embodiment of the present invention.

FIG. 6 is a longitudinal sectional view showing another embodiment of the electric fuel pump according to the present invention.

FIG. 7 is a longitudinal sectional view showing a conventional electric fuel pump.

FIG. 8 is a sectional view taken along the line CC of FIG. 7;

FIG. 9 is a characteristic curve showing the performance of a conventional electric fuel pump.

[Explanation of symbols]

1 pump casing assembly, 2a fuel return hole, 2b
Adjuster storage hole, 2c inner peripheral surface, 4 impeller (rotating body), 5 blades, 6 center shaft, 8 suction port, 9 discharge port, 15 motor, 16 rotor, 17, 18 bearing,
23 fuel outlet, 25 permanent magnet, 26 commutator, 2
7 brush for power supply, 30 pressure regulator, 31 valve,
31a elastic body, 31a1 fitting projection, 31b spring receiving, 31b1 fitting recess, 32 spring, 33
Spring holder, 33a Notch.

Claims (10)

[Claims] 1. A pump casing assembly for sucking fuel from an intake port and discharging it from a discharge port by rotation of a rotary body housed therein, an electric motor for rotating the rotary body, and internal combustion for fuel discharged from the discharge port. In an electric fuel pump including a fuel outlet discharged to an engine of an engine and a pressure regulator for adjusting a pressure of fuel discharged from the fuel outlet, the pressure regulator may be configured such that the fuel pressure discharged from the discharge outlet is An electric fuel pump, wherein the fuel pressure discharged from the fuel outlet is adjusted by returning fuel to the vicinity of the inlet when the pressure is equal to or higher than a predetermined pressure. 2. The electric fuel pump according to claim 1, wherein the pressure regulator is provided in a regulator accommodation hole of the pump casing assembly. 3. A pressure regulator, comprising: a valve for controlling a flow rate of fuel returned to the vicinity of the suction port based on a fuel pressure discharged from the discharge port; a spring for determining a pressure for opening and closing the valve; and a spring for holding the spring. The electric fuel pump according to claim 1, wherein the electric fuel pump is formed by a spring holder. 4. The electric fuel pump according to claim 3, wherein an elastic body is provided on a surface of the valve that contacts the pump casing body. 5. A valve, comprising: an elastic body having a fitting projection;
4. The electric fuel according to claim 3, wherein the elastic body and the spring receiver are formed by a spring receiver having a fitting recess, and the fitting protrusion is fitted into the fitting recess. pump. 6. A spring formed of a coil spring, one end of which is fitted to a valve and the other end of which is fitted to a spring holder, thereby integrally holding the valve and the spring holder. Item 3. The electric fuel pump according to Item 3. 7. The electric fuel pump according to claim 3, wherein the spring holder is fixed at a predetermined position on the inner peripheral surface of the adjuster housing hole. 8. The electric fuel pump according to claim 7, wherein a notch is provided in a peripheral portion of the spring holder. 9. The electric fuel pump according to claim 1, wherein the rotating body is an impeller having a blade portion on an outer peripheral portion. 10. An electric motor, comprising: a rotor having a central shaft engaged with a rotating body inserted therein; a bearing for supporting the central shaft and enabling the rotor to rotate; and a concentric outer periphery of the rotor. The electric fuel pump according to claim 1, wherein the electric fuel pump is formed by a pair of permanent magnets arranged in a shape, a commutator for supplying a current to a winding of the rotor, and a power supply brush.